Grafting Spiropyran Molecular Switches on TiO2: A First-Principles

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Grafting Spiropyran Molecular Switches on TiO: A First-Principles Study Anouar Belhboub, Florent Boucher, and Denis Jacquemin J. Phys. Chem. C, Just Accepted Manuscript • DOI: 10.1021/acs.jpcc.6b06447 • Publication Date (Web): 27 Jul 2016 Downloaded from http://pubs.acs.org on August 1, 2016

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The Journal of Physical Chemistry

Grafting Spiropyran Molecular Switches on TiO2: A First-Principles Study Anouar Belhboub,† Florent Boucher,‡ and Denis Jacquemin∗,†,¶ †Laboratoire CEISAM - UMR CNRS 6230, Université de Nantes, 2 Rue de la Houssinière, BP 92208, 44322 Nantes Cedex 3, France ‡Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2 Rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3, France ¶Institut Universitaire de France, 1, Rue Descartes, 75231 Paris Cedex 05, France E-mail: [email protected] Phone: +33 (0)2 51 12 55 64

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Abstract To explore the optoelectronic properties of spiropyran molecular switches adsorbed onto TiO2 anatase surfaces, we performed a DFT/TD-DFT study considering the two isomeric forms of the photochromes anchored by both their side. A comparison between the features of the hybrid and isolated systems is proposed to probe the adsorption effects on both subsystems. This comparison considered, on the one hand, the density of states and the alignment of the energy levels, and, on the other hand, the UV-visible spectra of these systems. We show that the several electronic and optical characteristics of the hybrid systems are modulated by the open/closed state of the photochromes. These properties are also modified by the localization of the anchor group on the photochrome.

Introduction Photochromism is a photochemical process allowing for a reversible change of the colors and other properties of molecules under the influence of external stimuli. 1–3 One well-known example of compounds undergoing this process is the colorless spiropyran (SP) which can be switched to its colored merocyanine (MC) form under UV irradiation that induces a CO bond cleavage. 4 The switching takes therefore place between a closed, nonplanar, poorly conjugated SP structure and an open, planar, highly delocalized MC structure 5,6 (see Scheme 1). The back reaction restoring the SP isomer can be induced by absorption of visible light or heat. The structural differences between the two isomers leads to significantly different physical and optical properties, 7 explaining why these systems have been the subject of considerable research works. For example, SPs have been used as building blocks in ionic sensors, 8–10 and have been applied to build switches 11 as well as to store data. 12 Clearly, the combination of these molecular photochromes with organic or inorganic materials is the key to the expansion of their applicability in realistic devices. 13–15 In this context, physisorption or chemisorption on surfaces is one of the possible strategies to build new hybrid systems able 2


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to take advantage of the physical properties of both subsystems. However, it is clear that a good understanding of the complete system is crucial to quantify the interplay between the photoisomerization process of the photochromes and the specific electronic structure of the surface. For instance, it has been shown in several investigations that different photochromes see their reversible switching process quenched when bound to metallic surfaces, 16–22 and this also holds for some SPs grafted on gold substrates. 23,24 However, in other cases, the photoswitching was conserved after grafting, as reported by Schulze et al. 25 Indeed, these authors showed that SPs on bismuth surfaces can continue undergoing their reversible ringopening/ring-closing cycles, and actually benefit from a photoactivity enhancement caused by the semi-metallic electronic structure of bismuth. It was also shown that SPs preserve their photochromic behavior when adsorbed onto porous silicon. 26 In fact, in a toluene solution containing silica particles, SP tend to photoadsorbe on the particles under their MC form generated by UV irradiation, while visible light causes desorption and retroisomerization to the SP form. In such situation, a modulation of the photoluminescence was also observed, with reversible changes in both the position and the intensity of the emission bands of the SP/porous silica systems, when the photoisomerization of the molecules took place. 27 We also underline that the non-covalent functionalization of graphene nanoribbons with SP photochromes has been achieved. 28 For this latter case, density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations showed that the photoisomerization of the SP molecules affects the electrostatic environment of the substrate, causing changes in the spin-polarization of the total system and allowing a control of the spin states. Following this logic of physical properties modulation by combining molecular photochromes with materials, metal oxides are interesting candidates as the science of their surfaces has been recently in the limelight due to their importance in several fields. 29–31 One of the most studied system in this group is titanium dioxide (TiO2 ). 32 Due to the valuable properties of its two most stable polymorphs, namely anatase and rutile, TiO2 was used in a large panel of fields, e.g., electronics, 33 catalysis, 34 gas-sensors 35 and of course solar-to-

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whereas, in the second part, the UV-vis spectra of the considered systems are treated. Finally, Section IV gives a general conclusion of this work.

Computational details All our ab initio calculations performed in the framework of DFT used the VASP code, 44 whereas the TD-DFT calculations were made with the Quantum Espresso code. 45 For the VASP calculations, the exchange-correlation effects were treated at the generalized gradient approximation (GGA) using the functional proposed by Pedrew, Burke and Ernzerhof (PBE). 46 Core electrons were replaced by projected augmented wave (PAW) potentials. 47 Valence electrons were described by a plane wave basis set, with a cutoff of 400 eV. Van der Waals corrections were systematically added, to take account of dispersive effects, using the empirical potential parametrized by Grimme (so-called DFT-D2). 48 Atomic positions of all systems were optimized, with no symmetry or spin polarization constraints, using a total energy threshold of 10−3 eV. The relaxed structures of the isolated photochromes were obtained considering only the Γ-point for the Brillouin zone integration and a vacuum size of more than 8 Å along the cell three Cartesian directions. For TiO2 , a first calculation was done for the bulk state with a Monkhorst-Pack k-point grid of 6×6×2, relaxing ions, cell shape and volume. Convergence was tested by comparing the optimized lattice parameters to previous PBE-based calculations. 41,49 Our values are in good agreement with those previous values, with a deviation of less than 1% (see the Supporting Information, SI). From the bulk system, a 2×5 anatase slab was cut in the (101) direction presenting dimensions of 21.01×19.01 Å2 in the (xy) plane. The slab was build as two stacked O-Ti-O layers, which has been shown to be a sufficient thickness for modeling anatase. 50,51 Constraints were applied during relaxation allowing only the top layer in direction (001) to relax, while the bottom layer was kept frozen. The hybrid systems were modeled following an approach described elsewhere for switches chemisorbed onto TiO2 , 49,52 where the photochromes are adsorbed perpendicu-

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larly onto the periodic anatase surface in a bridging position, with the oxygen atoms of the carboxylate anchor being chemisorbed onto titanium ions of the surface, as shown in Figure 1. The dissociated proton of the carboxylate was bonded to an oxygen atom of the surface with a distance of 7Å from the adsorption site, so to guarantee that there is no influence on the photochrome-surface interaction. 49 To avoid interactions with periodic replica, the considered surfaces provide a minimum distance of 10 Å and 16 Å for adsorbate-adsorbate periodicity in (xy) plane and adsorbate-surface periodicity in z direction, respectively. However, for MC1, the adsorbate-adsorbate periodicity distance is 6.7 Å in the y direction. In order to validate the non-interacting character in this case, we grafted the photochrome onto a larger 2×7 periodic surface so to reach an adsorbate-adsorbate separation of 14 Å in the y direction. Comparable total energies were obtained in both cases with a difference of 8.7×10−2 eV/atom (see the SI). The structural optimizations of the hybrid systems were performed using the Γ-point for k-sampling due to the large size of these systems. Convergence was tested with a 2×2×1 Monkhorst-Pack grid with total energy differences of less than 0.1 eV (see the SI). The relaxed structures were used to calculate the electronic density of states (DOS) with a Monkhorst-Pack k-point grid of 2×2×1 and a Gaussian smearing of 0.03 eV. In order to better describe the energy gap of our systems, often underestimated with PBE, we used in this case the GGA+U method with the PBE functional. A value of U=3 eV was used for titanium d orbitals, as it was shown previously to produce results comparable to those obtained with hybrid functionals in the case of bulk TiO2 anatase. 53 In a second stage, the absorption spectra for all periodic systems were calculated in two steps using the Quantum Espresso code. First, the electronic structure of the previously optimized structures was obtained using the PWscf package with the PBE functional. A convergence threshold of 10−5 Ry was adopted. Core electrons were simulated by ultrasoft pseudopotentials 54 and valence electrons were expanded on a plane-wave basis set with a cutoff energy of 25 Ry. Second, the polarizability tensor of the systems was calculated in the framework of Time-Dependent Density Functional Perturbation Theory (TD-DFPT) using

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Table 1: Energy gap of the MC1, MC2, SP1 and SP2 systems. The values of the Bader charge transfer are also given. System MC1 SP1 MC2 SP2

Eg (eV) qtransfer (e− /photochrome) 0.754 -0.0850 0.596 -0.0583 0.435 -0.0548 1.108 -0.1007

of the lowest unoccupied orbital taken as the first molecular band above the Fermi level in the PDOS) of the photochromes differ depending on the isomeric state, an expected outcome since the two isomers have obviously different electronic properties. Moreover, for the same isomer (MC or SP), E HOMO and E LUMO are also different when changing the anchoring side, though this latter effect is quantitatively smaller. When the photochromes are adsorbed, their energy levels are shifted due to the interaction with the surface, the magnitude of this effect being variable but not very large. Consequently, the differences in the gas-phase E HOMO and E LUMO between the photochromes are preserved after adsorption. This conservation is also confirmed by the small changes in the energy gap of the adsorbed photochromes compared to their gas-phase counterparts, ∆Egphotochrome = |Egphotochrome−ads − Egphotochrome−gas |, that is ca. 0.1 eV only or even lower (see Table 2). Figure 4 also provides the alignment of the ECB and EVB (energy of the valence band) of the surface considering the four hybrid systems. We notice that, due to the intersystem interactions, these energy levels are shifted (upshift for EVB and downshift for ECB ) in all hybrid systems by a similar value. In other words, after adsorption of the photochrome, the valence and conduction bands of the surface lie at almost the same energy levels as prior to adsorption (leading to the same bandgap as shown in Table 2) irrespective of the form of the photochrome. Giving the fact that, as mentioned above, the bandgap of the hybrid systems is defined by the E HOMO and ECB , and that ECB is almost constant for all hybrid systems, we can conclude that the differences in the energy gap between the hybrid systems are almost solely controlled by the

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profile. However, comparing the case of MC1 and MC2 or SP1 and SP2 we see that these states present significant differences regarding the number of the peaks. This is mainly due to the different charge redistribution obtained when changing the anchor localization on the molecular switch. From both sides of the surface energy gap, i.e., the valence and conduction band, the overlap with the surface states affects differently the molecular states of the various hybrid systems. One example of this difference is seen in the E LUMO of the photochrome that changes in height depending on the isomeric state and the anchoring site. These differences in the electronic coupling within the hybrid systems can impact the interplay between the subsystems, e.g., the photoexcited charge transfer. To continue in this direction, we calculated the electronic density exchanged upon adsorption as:

ρexchange = ρtotal − ρslab − ρphotochrome ,

(2)

where ρslab and ρphotochrome are, respectively, the charge densities of the surface and the photochrome using the structures directly extracted from the hybrid system. The results are illustrated in Figure 5. By comparing MC1 (Figure 5a) and SP1 (Figure 5c), we can see that the photochrome interacts more strongly with the surface under its extended MC form as the electronic density is more perturbed, compared to the SP form that only shows perturbation located close to the anchoring group. This is due, on the one hand, to the extended π-conjugation of the MC form, and, on the other hand, to the geometrical organization of MC1, with both moieties of the adsorbed photochrome being closer from the surface than in SP1 (see Figure 5). However, the exchanged electronic density in the case of SP2 and MC2 gives an ambiguous image. In fact, if we focus on the adsorbed photochromes, the perturbation of the electronic density seems to be more pronounced in the case of the adsorbed SP form. But in contrast, the electronic density of the surface is more affected by the interaction with the adsorbed MC form. To reach a more quantitative value to this intersystem electronic exchange, we calculated the Bader charge transfer

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surface is independent of the functionalization site of the anchor on the photochrome. Indeed, in the considered region, we notice small redshifts (around −0.05 eV) when comparing the SP1 and SP2 adsorbed and bare surface spectra, that is very similar optical responses. However, since the SP isomer does not present any absorption bands in the visible range, the spectral features of the adsorbed molecule are completely buried under the much more intense contributions of the titania surface. In the case of the MC form (upper panels of Figure 7), the experimental absorption spectrum of the isomer in solution is dominated by a band at ∼ 2.06-2.25 eV. 14 The corresponding calculated band is located at ca. 2.15 eV as shown in the insets of Figure 7. This band is attributed to a delocalized cyanine-like π-π ∗ transition which include contributions coming from HOMO and/or HOMO−1 towards LUMO and/or LUMO+1, with a dominant HOMO-LUMO character. 58,59 When the photochrome is adsorbed, this band is significantly shifted with a noticeable dependence on the anchoring group position. In fact, while for MC2 the peak is almost at the same energy (+0.03 eV) compared to that of the isolated photochrome, an important redshift of about −0.32 eV is obtained in the case of MC1. Due to the dependency of the intersystem electronic interaction on the anchoring side (as shown by the PDOS calculations), the electronic structure of the molecular switch is altered differently in MC1 and MC2. The dominant HOMO-LUMO contribution in the gas-phase spectra of the MC isomer is preserved in the adsorbed-phase for the MC2 switch. In contrast, another contribution probably governs this π-π ∗ transition in MC1, leading to a different absorption energy of the first band. This is in line with the results discussed before showing that the photochrome is more perturbed by the surface in MC1 compared to MC2 based on the electronic density difference and Bader charge transfer calculations. Finally, as in the case of SP-based hybrid systems, the optical features of the surface are also similarly affected by adsorption of the MC photochrome considering both anchoring sides, with redshifts of about −0.1 eV when compared to the spectral contributions of the bare surface.

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showed dependence on both the isomeric state and the anchoring side as illustrated by the values of the charge transfer. Interestingly, when bonded through the chromene moiety (MC1 and SP1), the photochrome exchange more with the slab under the MC form compared to the SP form, while the opposite occurs when grafting is performed via the indoline moiety (MC2 and SP2). It was also shown that this dependency is also found in the optical properties of the hybrid systems. Indeed, the comparison of the absorption spectra between the isolated and hybrid MC-based systems showed that changing the anchoring side is sufficient to alter the response of the systems: the gas-phase switch features, mainly in the visible range, were noticeably influenced in the adsorbed-phase, especially for MC1 that showed an important shift of the first absorption band due to a stronger interaction with the surface. Therefore, the optical contrast between SP1 and MC1 is enhanced with the surface. A clear limitation of this study is the selection of a GGA for all calculations. The use of hybrid functionals would certainly provide more quantitative estimates, especially for the determination of the positions of UV/Vis absorption band. We are currently performing additional works devoted to photochromes grafted on surfaces with more redined DFT and TD-DFT models.

Supporting Information Available Bond lengths of all the isolated and adsorbed photochromes. Optimized TiO2 bulk lattice parameters and comparison with previous works. Energetic comparison for MC1 using a 2×5 and 2×7 slab. Validation of the Γ-point calculations. Bandgap comparisons using PBE and PBE+U methods.

This material is available free of charge via the Internet at

http://pubs.acs.org/.

Acknowledgement A.B. acknowledges the European Research Council (ERC, Marches 278845 grant) for sup17



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porting his post-doctoral position. D.J. acknowledges the European Research Council (ERC) and the Région des Pays de la Loire for financial support in the framework of a Starting Grant (Marches - 278845) and the LumoMat project, respectively. This research used resources of i) the GENCI-CINES/IDRIS; ii) CCIPL (Centre de Calcul Intensif des Pays de Loire); iii) a local Troy cluster and iv) HPC resources from ArronaxPlus (grant ANR-11-EQPX-0004 funded by the French National Agency for Research).

References (1) Irie, M. Photochromism: Memories and Switches Introduction. Chem. Rev. 2000, 100, 1683–1684. (2) Russew, M.-M.; Hecht, S. Photoswitches: From Molecules to Materials. Adv. Mater. 2010, 22, 3348–3360. (3) Zheng, Y. B.; Pathem, B. K.; Hohman, J. N.; Thomas, J. C.; Kim, M.; Weiss, P. S. Photoresponsive Molecules in Well-Defined Nanoscale Environments. Adv. Mater. 2013, 25, 302–312. (4) Berkovic, G.; Krongauz, V.; Weiss, V. Spiropyrans and Spirooxazines for Memories and Switches. Chem. Rev. 2000, 100, 1741–1754. (5) Feringa, B. L. The Art of Building Small: From Molecular Switches to Molecular Motors. J. Org. Chem. 2007, 72, 6635–6652. (6) Klajn, R.; Stoddart, J. F.; Grzybowski, B. A. Nanoparticles Functionalised with Reversible Molecular and Supramolecular Switches. Chem. Soc. Rev. 2010, 39, 2203–2237. (7) Perry, A.; Green, S. J.; Horsell, D. W.; Hornett, S. M.; Wood, M. E. A Pyrene-Appended Spiropyran for Selective Photo-Switchable Binding of Zn(II): UV–Visible and Fluores-

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Page 19 of 25

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


cence Spectroscopy Studies of Binding and Non-Covalent Attachment to Graphene, Graphene Oxide and Carbon Nanotubes. Tetrahedron 2015, 71, 6776–6783. (8) Xie, X.; Mistlberger, G.; Bakker, E. Reversible Photodynamic Chloride-Selective Sensor Based on Photochromic Spiropyran. J. Am. Chem. Soc. 2012, 134, 16929–16932. (9) You, Q.-H.; Fan, L.; Chan, W.-H.; Lee, A. W. M.; Shuang, S. Ratiometric SpiropyranBased Fluorescent pH Probe. RSC Adv. 2013, 3, 15762–15768. (10) Fries, K.; Samanta, S.; Orski, S.; Locklin, J. Reversible Colorimetric Ion Sensors Based on Surface Initiated Polymerization of Photochromic Polymers. Chem. Commun. 2008, 6288–6290. (11) Raymo, F. M.; Giordani, S. Signal Processing at the Molecular Level. J. Am. Chem. Soc. 2001, 123, 4651–4652. (12) Kawata, S.; Kawata, Y. Three-Dimensional Optical Data Storage Using Photochromic Materials. Chem. Rev. 2000, 100, 1777–1788. (13) Kortekaas, L.; Ivashenko, O.; van Herpt, J. T.; Browne, W. R. A Remarkable Multitasking Double Spiropyran: Bidirectional Visible-Light Switching of Polymer-Coated Surfaces with Dual Redox and Proton Gating. J. Am. Chem. Soc. 2016, 138, 1301– 1312. (14) Klajn, R. Spiropyran-Based Dynamic Materials. Chem. Soc. Rev. 2014, 43, 148–184. (15) Li, Y.; Zhang, H.; Qi, C.; Guo, X. Light-Driven Photochromism-Induced Reversible Switching in P3HT-Spiropyran Hybrid Transistors. J. Mater. Chem. 2012, 22, 4261– 4265. (16) Henningsen, N.; Franke, K. J.; Torrente, I. F.; Schulze, G.; Priewisch, B.; RückBraun, K.; Dokić, J.; Klamroth, T.; Saalfrank, P.; Pascual, J. I. Inducing the Ro-

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tation of a Single Phenyl Ring with Tunneling Electrons. J. Phys. Chem. C 2007, 111, 14843–14848. (17) Henzl, J.; Bredow, T.; Morgenstern, K. Irreversible Isomerization of the Azobenzene Derivate Methyl Orange on Au(111). Chem. Phys. Lett. 2007, 435, 278–282. (18) Alemani, M.; Selvanathan, S.; Ample, F.; Peters, M. V.; Rieder, K.-H.; Moresco, F.; Joachim, C.; Hecht, S.; Grill, L. Adsorption and Switching Properties of Azobenzene Derivatives on Different Noble Metal Surfaces: Au(111), Cu(111), and Au(100). J. Phys. Chem. C 2008, 112, 10509–10514. (19) Wang, Y.; Ge, X.; Schull, G.; Berndt, R.; Bornholdt, C.; Koehler, F.; Herges, R. Azo Supramolecules on Au(111) with Controlled Size and Shape. J. Am. Chem. Soc. 2008, 130, 4218–4219. (20) Wolf, M.; Tegeder, P. Reversible Molecular Switching at a Metal Surface: A Case Study of Tetra-Tert-Butyl-Azobenzene on Au(111). Surf. Sci. 2009, 603, 1506–1517. (21) Piantek, M.; Miguel, J.; Krüger, A.; Navio, C.; Bernien, M.; Ball, D. K.; Hermann, K.; Kuch, W. Temperature, Surface, and Coverage-Induced Conformational Changes of Azobenzene Derivatives on Cu(001). J. Phys. Chem. C 2009, 113, 20307–20315. (22) Leyssner, F.; Hagen, S.; Óvári, L.; Dokić, J.; Saalfrank, P.; Peters, M. V.; Hecht, S.; Klamroth, T.; Tegeder, P. Photoisomerization Ability of Molecular Switches Adsorbed on Au(111): Comparison between Azobenzene and Stilbene Derivatives. J. Phys. Chem. C 2010, 114, 1231–1239. (23) Bronner, C.; Schulze, G.; Franke, K. J.; Pascual, J. I.; Tegeder, P. Switching Ability of Nitro-Spiropyran on Au(111): Electronic Structure Changes as a Sensitive Probe During a Ring-Opening Reaction. J. Phys.: Condens. Matter 2011, 23, 484005.

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(24) Shiraishi, Y.; Shirakawa, E.; Tanaka, K.; Sakamoto, H.; Ichikawa, S.; Hirai, T. Spiropyran-Modified Gold Nanoparticles: Reversible Size Control of Aggregates by UV and Visible Light Irradiations. Appl. Mater. Interf. 2014, 6, 7554–7562. (25) Schulze, G.; Franke, K. J.; Pascual, J. I. Induction of a Photostationary RingOpening/Ring-Closing State of Spiropyran Monolayers on the Semimetallic Bi(110) Surface. Phys. Rev. Lett. 2012, 109, 026102. (26) Okabe, Y.; Ogawa, M. Photoinduced Adsorption of Spiropyran into Mesoporous Silicas as Photomerocyanine. RSC Adv. 2015, 5, 101789–101793. (27) Lee, C.-Y.; Hu, C.-H.; Cheng, S.-L.; Chu, C.-C.; Hsiao, V. K. Reversible Photoluminescence in Spiropyran-Modified Porous Silicon. J. Lumin. 2015, 159, 246–250. (28) Wong, B. M.; Ye, S. H.; O’Bryan, G. Reversible, Opto-Mechanically Induced SpinSwitching in a Nanoribbon-Spiropyran Hybrid Material. Nanoscale 2012, 4, 1321–1327. (29) Freund, H.-J. Adsorption of Gases on Complex Solid Surfaces. Angew. Chem. Int. Ed. 1997, 36, 452–475. (30) Campbell, C. T. Ultrathin Metal Films and Particles on Oxide Surfaces: Structural, Electronic and Chemisorptive Properties. Surf. Sci. Reports 1997, 27, 1–111. (31) Bonnell, D. A. Scanning Tunneling Microscopy and Spectroscopy of Oxide Surfaces. Prog. Surf. Sci. 1998, 57, 187–252. (32) Diebold, U. The Surface Science of Titanium Dioxide. Surf. Sci. Reports 2003, 48, 53–229. (33) Wu, J.-M.; Chen, C.-J. Effect of Powder Characteristics on Microstructures and Dielectric Properties of (Ba,Nb)-Doped Titania Ceramics. J. Am. Ceram. Soc. 1990, 73, 420–424.

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(34) Mills, A.; Hill, G.; Bhopal, S.; Parkin, I. P.; O’Neill, S. A. Thick Titanium Dioxide Films for Semiconductor Photocatalysis. J. Photochem. Photobio. A: Chemistry 2003, 160, 185 – 194. (35) Varghese, O. K.; Grimes, C. A. Metal Oxide Nanoarchitectures for Environmental Sensing. J. Nanosc. Nanotech. 2003, 3, 277–293. (36) Xie, X.; Bakker, E. Photoelectric Conversion Based on Proton-Coupled Electron Transfer Reactions. J. Am. Chem. Soc. 2014, 136, 7857–7860. (37) Sayama, K.; Tsukagoshi, S.; Hara, K.; Ohga, Y.; Shinpou, A.; Abe, Y.; Suga, S.; Arakawa, H. Photoelectrochemical Properties of J Aggregates of Benzothiazole Merocyanine Dyes on a Nanostructured TiO2 Film. J. Phys. Chem. B 2002, 106, 1363–1371. (38) Li, L.; Yu, M.; Li, F. Y.; Yi, T.; Huang, C. H. INHIBIT Logic Gate Based on Spiropyran Sensitized Semiconductor Electrode. Colloids Surf. A: Physicochem. Eng. Asp. 2007, 304, 49–53. (39) Dryza, V.; Bieske, E. J. Electron Injection and Energy-Transfer Properties of Spiropyran–Cyclodextrin Complexes Coated onto Metal Oxide Nanoparticles: Toward Photochromic Light Harvesting. J. Phys. Chem. C 2015, 119, 14076–14084. (40) Ma, S.; Ting, H.; Ma, Y.; Zheng, L.; Zhang, M.; Xiao, L.; Chen, Z. Smart Photovoltaics Based on Dye-Sensitized Solar Cells Using Photochromic Spiropyran Derivatives as Photosensitizers. AIP Adv. 2015, 5, 057154. (41) Labat, F.; Baranek, P.; ; Adamo, C. Structural and Electronic Properties of Selected Rutile and Anatase TiO2 Surfaces: an ab Initio Investigation. J. Chem. Theo. Comput. 2008, 4, 341–352. (42) Angelis, F. D.; Fantacci, S.; Gebauer, R. Simulating Dye-Sensitized TiO2 Heterointer-

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Page 22 of 25

Page 23 of 25

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


faces in Explicit Solvent: Absorption Spectra, Energy Levels, and Dye Desorption. J. Phys. Chem. Lett. 2011, 2, 813–817. (43) Thomas, A. G.; Syres, K. L. Adsorption of Organic Molecules on Rutile TiO2 and Anatase TiO2 Single Crystal Surfaces. Chem. Soc. Rev. 2012, 41, 4207–4217. (44) Kresse, G.; Furthmüller, J. Efficiency of Ab-Initio Total Energy Calculations for Metals and Semiconductors using a Plane-Wave Basis Set. Comput. Mater. Sci. 1996, 6, 15–50. (45) Giannozzi, P.; Baroni, S.; Bonini, N.; Calandra, M.; Car, R.; Cavazzoni, C.; Ceresoli, D.; Chiarotti, G. L.; Cococcioni, M.; Dabo, I. et al. QUANTUM ESPRESSO: a Modular and Open-Source Software Project for Quantum Simulations of Materials. J. Phys.: Condens. Mat. 2009, 21, 395502. (46) Perdew, J. P.; Burke, K.; Wang, Y. Generalized Gradient Approximation for the Exchange-Correlation Hole of a Many-Electron System. Phys. Rev. B 1996, 54, 16533– 16539. (47) Blöchl, P. E. Projector Augmented-Wave Method. Phys. Rev. B 1994, 50, 17953–17979. (48) Grimme, S. Semiempirical GGA-Type Density Functional Constructed ith a LongRange Dispersion Correction. J. Comput. Chem. 2006, 27, 1787–1799. (49) Chen, K. J.; Charaf-Eddin, A.; Selvam, B.; Boucher, F.; Laurent, A. D.; Jacquemin, D. Interplay between TiO2 Surfaces and Organic Photochromes: A DFT Study of Adsorbed Azobenzenes and Diarylethenes. J. Phys. Chem. C 2015, 119, 3684–3696. (50) Martsinovich, N.; Jones, D. R.; Troisi, A. Electronic Structure of TiO2 Surfaces and Effect of Molecular Adsorbates Using Different DFT Implementations. J. Phys. Chem. C 2010, 114, 22659–22670. (51) Angelis, F. D.; Fantacci, S.; Mosconi, E.; Nazeeruddin, M. K.; Grätzel, M. Absorption

23



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Spectra and Excited State Energy Levels of the N719 Dye on TiO2 in Dye-Sensitized Solar Cell Models. J. Phys. Chem. C 2011, 115, 8825–8831. (52) Chen, K. J.; Boucher, F.; Jacquemin, D. How Adsorption Onto TiO2 Modifies the Properties of Multiswitchable DTE Systems: Theoretical Insights. J. Phys. Chem. C 2015, 119, 16860–16869. (53) Finazzi, E.; Di Valentin, C.; Pacchioni, G.; Selloni, A. Excess Electron States in Reduced Bulk Anatase TiO2 : Comparison of Standard GGA, GGA+U, and Hybrid DFT Calculations. J. Chem. Phys. 2008, 129, 154113. (54) Laasonen, K.; Car, R.; Lee, C.; Vanderbilt, D. Implementation of Ultrasoft Pseudopotentials in ab initio Molecular Dynamics. Phys. Rev. B 1991, 43, 6796–6799. (55) Malcioglu, O. B.; Gebauer, R.; Rocca, D.; Baroni, S. TurboTDDFT, A Code for the Simulation of Molecular Spectra using the Liouville-Lanczos Approach to TimeDependent Density-Functional Perturbation Theory. Comput. Phys. Commun. 2011, 182, 1744–1754. (56) Bader, R. F. W. Atoms in Molecules. A Quantum Theory; Clarendon Press, Oxford, 1990. (57) Garcia, G.; Adamo, C.; Ciofini, I. Evaluating Push-Pull Dye Efficiency Using TD-DFT and Charge Transfer Indices. Phys. Chem. Chem. Phys. 2013, 15, 20210–20219. (58) Guillaume, M.; Champagne, B.; Zutterman, F. Investigation of the UV/Visible Absorption Spectra of Merocyanine Dyes Using Time-Dependent Density Functional Theory. J. Phys. Chem. A 2006, 110, 13007–13013. (59) Shiraishi, Y.; Adachi, K.; Itoh, M.; Hirai, T. Spiropyran as a Selective, Sensitive, and Reproducible Cyanide Anion Receptor. Org. Lett. 2009, 11, 3482–3485.

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Grafting Spiropyran Molecular Switches on TiO2: A First-Principles

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